WISE Lights Up Orion's Blazing Sword

Of all the constellations in the night sky the most well-known has to be Orion, the cosmic hunter with an eternal broad-shouldered stance and shining belt of three brilliant stars. Positioned just below Orion’s belt is a perpendicular line of dimmer stars that represent his sword, but the center “star” in Orion’s sword isn’t a star at all — rather, it’s an entire star factory, an enormous cloud of gas and dust glowing with the light of newborn stars fresh from their creation.

One of the most spectacular naked-eye objects in the night sky, the Great Nebula in Orion is just a part of an even larger structure of star-forming gas that drifts across the famous constellation. Many times the width of the full moon in the sky, it can’t be seen by our eyes — but NASA’s orbiting Wide-Field Infrared Explorer (WISE) reveals its glowing beauty.

WISE image of the heart of the Orion nebula (M42)

The dramatic image above shows the region of the Great Nebula in Orion (aka Messier 42) as seen by WISE, which is sensitive to the slightest amount of heat given off by cosmic objects. The dust that drifts between the stars is illuminated green here, billowing in vast clouds and waves that are blown in all directions by powerful stellar winds streaming from the bright young stars clustered near the center of the nebula.

Eventually, other portions of these clouds will cool and collapse into themselves, igniting more new stars which will continue the process. What we see today is just a brief snapshot of our galaxy’s star-forming process in action.